Ablation devices can be used to treat tumors in the body. In particular, ablation devices can be used to treat benign prostatic hypertrophy or hyperplasia (BPH), a condition resulting in an enlargement of the prostate gland. This is a common medical problem typically experienced by men over 50 years of age. Hyperplastic enlargement of the prostate gland often leads to compression of the urethra, which results in obstruction of the urinary tract.
An ablating needle can be used with a cystoscope to treat BPH by ablating a prostatic adenoma, which is a benign tumor inside the prostate. To perform the ablation procedure, a physician inserts a distal end of the cystoscope into the urethra of a patient while viewing the advance through an eye piece of the cystoscope. The needle electrode is also introduced into the urethra through a working channel of the cystoscope. The cystoscope and the needle electrode are typically introduced inside the urethra sequentially. The distal end of the needle electrode is positioned adjacent the prostate near the prostatic adenoma. The physician then causes the needle electrode to penetrate the urethral wall, such that it is positioned inside the prostatic adenoma. Radiofrequency (RF) energy is applied to the needle electrode to coagulate tissue surrounding the electrode. Coagulation causes necrosis of the prostatic adenoma, resulting in atrophy of the prostate and a reduction in the compressive forces that interfere with urine flow through the urethra.
During the ablation procedure, it is important that the needle electrode be positioned precisely, because inaccurate electrode placement can cause incontinence in the patient. Visualization is typically provided by inserting the needle electrode through a cystoscope. One disadvantage of the ablation device insertable through a cystoscope is that it is difficult to feed the device through a working channel of the cystoscope and requires a lot of juggling which can make accurate placement of the needle electrode difficult. Moreover, it is often difficult to observe the distal tip of the needle electrode as the electrode penetrates the urethral wall, because the distal end of the electrode is typically deflected in order to penetrate the urethral wall while the viewing device itself does not deflect along with the needle electrode.
Existing interstitial ablation systems are also uncomfortable for the patients and cumbersome for the physician performing the procedure. Most cystoscopes and ablation systems integrating imaging devices tend to be rigid and uncomfortable for patients when inserted through a body lumen such as the urethra. The systems also have numerous knobs and dials that the physician must adjust for controlling needle deployment, fluid introduction, and application of RF energy.
Thus, there remains a need for an interstitial ablation device that provides accurate electrode placement and better control of the electrode, reduces patient discomfort and simplifies the process of performing ablation.